samples: kmemleak: print the raw pointers for debugging purposes

The kmemleak-test.c module is meant to leak some pointers for debugging
the kmemleak detection, pointer information dumping.  It's no use if it
prints the hashed values of such pointers.

Change the printk() format from %p to %px.  While at it, also display the
raw __percpu pointer rather than this_cpu_ptr() since kmemleak now tracks
such pointers independently of the standard allocations.

Link: https://lkml.kernel.org/r/20250206114537.2597764-3-catalin.marinas@arm.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>